Del Potro ends challenge of India's Devvarman

World number seven Juan Martin Del Potro pounded India's Somdev Devvarman 6-4 6-4 in the Dubai Championships second round on Wednesday, keeping the Argentine on course for a semi-final showdown with Novak Djokovic.

Del Potro saved three break points in his opening two service games, but was otherwise largely untroubled in dispatching India's number one.

"It's good, but I need to improve … if I want to have a chance of winning this tournament," Del Potro said in a courtside interview.

"The former U.S. Open champion was taken to a deciding set tiebreak by Cypriot Marcos Baghdatis in Tuesday's first round, saving three matches points along the way, but the Argentine was steadier against Devvarman, sealing the first set with an ace.

Roared on by a raucous Indian following in the stands, Devvarman provided more resistance in second before a long backhand sealed his fate.

Del Potro, 24, lost a year of his career with a wrist problem and he admitted the fear of aggravating the injury was causing him to change his playing style.

"Sometimes I get frustrated because I can't hit the ball like I want it," the Argentine told reporters. "I'm not going to put myself at risk again."

He will now face Daniel Brands after the German qualifier stunned former Dubai finalist Mikhail Youzhny 6-4 6-4.

The Czech toiled more than the score line would suggest, squandering five set points in the first set against the world number 90 and saving 12 of 14 break points himself.

The 2010 Wimbledon finalist eventually sealed the opening set as a flailing Kamke could only scuff a forehand into the net.

The second set was more straightforward, but the world number six will have to be more ruthless if he is to add to his eight career singles titles, especially as Roger Federer potentially awaits in the semi-final.

"I was struggling a bit with the conditions," Berdych told reporters. "Maybe the court is not extremely fast, but once it's really hot in the sun it really makes the balls fly much more than I'm used to."

Later on Wednesday, Federer will play Spain's Marcel Granollers, while Djokovic faces another Spaniard Roberto Bautista Agut.